Controller



June 14, 1960 N, F. BROWN ETAI- 2,940,477

CONTROLLER Filed oct. s, 1955' 7 sheets-sheet 1 June 14, 196() Filed Oct. 3, 1955 N. F'.v BROWN ETAL CONTROLLER 7 Sheets-Sheet 2 MIM/K9?,

`une 14, 196() N. F. BROWN ErAL 2,940,477

CONTROLLER Filed Oct. 3, 1955 '7 Sheets-Sheet 3 Nor/77 an /L fo wf? C`// ffora /l// Pe fers June 14, 1960 N. F. BROWN EFA; 2,940,477

CONTROLLER Filed Oct. 3, 1955 7 Sheets-Sheet 4 90 WMM/w?? June 14, 1960 N. F. BROWN ErAL 2,940,477

CONTROLLER Filed Oct. 3, 1955 '7 Sheets-Sheet 5 l 43 c 43 b .90 43a 16C .9/ /Vorman E Erol/vn C`//fford /1/1'. PeZe/s NVENTORS June 14, 1960 N. F. BROWN ETA!- 2,940,477

CONTROLLER Filed Oct. 3, 1955 T Sheets-Sheet 6 Norma/7 E Erol/vn /Poef/ W 7//7/7//79 NVENTORS BY @W7/MMX 7W ATTORNEYS June 14, 1960 N. F. BROWN ETAI- 2,940,477

CONTROLLER Filed Oct. 3, 1955 7 Sheets-Sheet 7 I MMA?? Uro/wf VJ nited States Patent O CONTROLLER Norman F. Brown and Clifford M. Peters, Longview, and Robert W. Dinning, Kilgore, Tex., assignors to Gfa'lrett Oil Tools, Inc., Longview, Tex., a corporation n exas Filed Oct. 3, 1955, Ser. No. 537,970

6 Claims. (Cl. 137-624.19)

.'Ihis invention relates to improvements in controllers and refers more particularly to controllers in which time provides the basic control and which are particularly adaptable for use in controlling iiow of well uids in various manners.

The controller of this invention can be used in a variety of industrial applications where a number of pneumatically powered two-way or three-way motor valves are required to be operated by remote control at selected times in relation to a common time base and for selected durations of time.

Another object is to provide a controller utilizing a pilot valve for alternately supplying gas under pressure to a control device and exhausting it from such device to the atmosphere in which a resilient means is employed to hold the pilot valve in one position and a means is provided for over-riding the resilient means at timed intervals to allow pilot valve to assume the other position and thus provide a timed control.

Another object is to provide a controller of the type set out in the preceding paragraph wherein the means for over-riding the resilient means includes a link attached to a weight which is slowly lifted, or a spring which is slowly compressed, over an appreciable time interval by a clock in such a way that although the power of the clock is insufficient to supply directly and instantaneously enough force to overcome the primary force keeping the pilot valve in said one position, it can, over a much longer space of time due to a mechanical advantage or cam-like linkage, raise the weight or compress the spring which when released provides a force suicient to override the resilient force instantaneously with a snap action.

Another object is to provide in a controller of the ty'pe mentioned in the last paragraph, for a ratchet which rises slowly and engages with the resilient means to over-ride it as aforesaid and which is itself capable of being disengaged from the resilient means by the application of a comparatively small force and in a manner that the resilient means can return the pilot valve to said one position with a snap action.

Another object is to provide a controller employing a pilot volve which is opened and closed with a snap action eliminating a constant bleeding of the control gas to the atmosphere and minimizing the amount of gas lost to the atmosphere upon each change.

Another object is to provide a controller for supplying an impulse signal throughout a predetermined timel interval which impulse may be terminated during the time interval in response to a rise or fall of pressure in a control fluid.

Another object is to provide a controller of the type employing a pilot valve with a means for over-riding the controller by remote control through the medium of a small pneumatic motor responding to a pressure signal initiated remotely from the controller.

Another object is to provide a clock controlled mechanism having a timing wheel, driven by the clock at a selected speed between one revolution per hour and one 'revolution per month, wherein the timing wheel has two peripheral grooves each formed with at least 180 regularly spaced slots for the retention of pins therein and arranged to cooperate with the formation of the rim of the timing wheel so as to be self-retaining but easily removable by hand, and a weight bar or equivalent springpressed arm hinged at one end, itted with an inclined plane or cam projecting down into the iirst of the peripheral grooves and shaped like a saw-tooth so tht a pin placed in a slot across the groove will, as the wheel rotates, slowly lift the weight bar or spring arm as the pin passess along the inclined face of the cam and then allow the bar to drop by gravity or the spring force as the pin passess the end of the cam. The weight bar has pivoted to it a ratchet toothed lever which, while rising with the weight bar, engages, without moving, the spring means holding the pilot in closed position but capable upon falling of the weight bar or spring-pressed arm of overcoming the spring force holding the pilot in one position whereby the pilot may change its position automatically. The ratchet toothed lever has a crank means secured to it with a saw-toothed profile cam that projects into the second peripheral groove in the timing wheel so that a pin placed in the slot across this groove will, as the wheel rotates, engage and lift this crank to rotate the ratchet toothed lever to disengage the valve closing spring means. The ratchet toothed lever provides a catch which may be disengaged from the spring means by other means as, for example, (l) by means sensitive to a rise in pressure, (2) by means sensitive to a fall in pressure, and (3) by a mechanical trip either acting directly or through the medium of a pneumatic motor responsive to remotely initiated signals.

Another object is to provide a controller for generatingV timed impulses of a selected time duration with means for interrupting any of the generated impulses during its. usual time period and terminating the impulse in response to occurrence of a control condition. v

Another object is to provide a time controller for automatically delivering a pressure impulse at selected time intervals for a selected time duration in which any impulse may be terminated short of its pre-selected time duration upon occurrence of a pre-selected condition.

- Another object is to provide a controller for delivering pressure impulses of a predetermined duration at predetermined time intervals with means for interrupting either a particular impulse or successive impulses upon occurrence and during the existence of a predetermined pressure condition in which the impulses will continue to be given after cessation of the occurrence of such predetermined condition at their regular time intervals as though there had been no previous interruption in the timing cycle.

Another object is to provide a controller and system utilizing a pilot valve `for providing an opening force, which pilot valve is controlled by a resilient means and a means 'for rendering the resilient means ineffective, wherein the latter means may be responsive to several conditions as well .as time dependent upon which condition occurs first and independently of the others, for example, a cycle inititated by a clock timing wheel can be ended .by the arrival of a free piston at the tubing head of a well, failing which, it can be ended by a fall in the gas pressure in the casing of the same well, yfailing which, it can be ended .by the clock timing wheel on the expiration of a predetermined time; whichever condition or eiiect occurs clirst terminating the cycle. A

Another .object of Ithe invention is to provide a time controlled controller for both starting and terminating an operation which employs a safety factor in that upon stoppage of the clock in the middle of such an operation which would leave a valve open indeiinitely, the oper- Y Whereinz" mechanism.

a ation is terminated .at substantially the same time that it would .be terminated by the clock hadY the clocknot stopped in response to `occurrence ofrsorne condition such as pressure change or arrival of a mechanical part at a predetermined station; f Other `and yfurther objects of the invention Y illustrating Aone `preferred embodiment ofA the controller ofV lthisr invention which is responsive strictly .to a-time' control;

will appearA from a consideration" of the 'specification and the drawj ings. f

' means. The blade'spring is'xed to bracket 47 and adjusted in strength by Vrotating the bar 47 and looking same by screw 63. Thus, the spring 62fpresses valve 31 against Vseat 30 .closing off thesupply of gas vand simultaneously Y opening the exhaust port 32:

Attached I11.11ierrleatll "hhwlekbass 6 4fiSff11 Central colunnfSgof thexedvdistributordisc 37 which consti- Y tutes agstator. Thegstaitor hasta raised eircular valving face 65 and Va number, typically'irom twentyftof'forty according to .the number of valvesorother devices .to be f Fig. .5 vis an elevational f view with parts shown in se'c-Y Y tion oftheicontroller illustrated in Fig. 4 and rotated 90 from the View of Fig. 4;

lFig.f6 is aview taken in elevation with parts shown'in t section of amodied controller similar to that shown in Fig'sf4`and5 showing the controller equipped for tripping not only ontime but also in responseito pressure and ,a mechanicalV action;

Fig.Y 7V` is a top Yplan -vieW of the controller shown'rin Fig. 6; and Y Fig. 8 is* an elevational: View taken atl 90 from the view in Fig. 6V and illustrates in section part of the control Referring now to Figs. 4 and 5, aclock 42,rotatesV a control wheel 43 atV a speed suitedl .to theV installation to vbe controlled.Y The wheel-43 has two peripheral grooves 43a andr43b, a large number of slots 43c, typif cally- 180 or 240,` conveniently divisibleby 30 Y(days) or by 12 (hours), and shaped spring pins 44 `capable oi being 'placedin any' groove and self-retaining by ,virtue f ofla lightgrip in the circumferential recess l45',.a.reutilized;

'An upright standard orback plate 46 carries axveight bar' bracket 47 Ywhose extension;pin 48 is apivotouVVV whichV a weightrbar 49 can swing in a verticalplaneA over the of'wheel' 43. VA stop 53^limits downward swinginfg of the Weight bar relative to .the WheeL II-he-camf 50, movable in a slot 51 inthe 4weight ,barand having all slack taken up. by :a bladefspringSZ,v projects down-into the wheelgroove 43a and interceptsY thel path of-any pin 44'plac`ed`in any slot `43e when the' weight-:bar lis at res-t (instep/53. Rot-ation of the Wheel 43 and-pins'then theweight Shar slowly and dropsV it instantaneously when the`pin` has` passed the Yfull'leugth of-cam 50. The

position ofcam 50 is varied :by the Itine thread screw` ,54,

' Veidto aA-tiine1ieleaselV lever 59l which" al carril V59a fs'imilar'lto the' carri 50.- Y'Ille arrangementis such :that rockingrof leverj59 due to earn .59a engaginga pin 44 will cause the lever 58 to rock to release catchn 58a. vCam controlled, of holes `66 `aiially'drilled' and' evenly spaced on a common(radius.Y .the holes are arranged circumferentially of the stator.V To the holes 66 will be connected small pipes, typically one-quarter inch standard copper tubing leading to valve or other device tobecontrolled: Y f :j The rotat g discfdistributorfor rotor 36`is mounted for turningabout the tilted central column 3 5 and isv held in close contact with fixed'disc or stator 37Eby ,a spring 6 7.V 'The rotatingfffriction is relieved by thrustball bear- Vinglls and protectedrfrom'dust byrsleeve69. Y Y Y Pressure gas from pilot` Valve 3=1-is conducted by pipes 33 .and 34 tophole '70 inthe column 3S. A radially drilled hole 71 connects hole '70 with a circumferential groove 72. Groove 72 is isolated within close V-iitting bore Y73` of rotating disc '36 by two seals'7f4 above and below the groove`72-respectively. Onfthe same plane as radial hole 71 is a radially extending hole 715 passing through one radius of the rotating disc 36 Iand extending from bore'73 to therouter periphery Where itis closed by plug 76. At the same radius as hole I66in the xed disc,` one port 777 isY yaxially drilled inthe rotating disc 36 front-the hole 75 tofthe surface in contact with the raised` Avalving face 65 ofthe fixed ,discr3`f7' and an annula'rly recessed seal ringf78,provides*a pressure seal so .that pressure gaS from the pilotrvalve can be delivered by pipes133 and 34,.-holesi-70, 71, 75and 7,7to any port 66, withA which portV 1 7Vis broughtinto-alignrnent or register, substantially Without leakage, Afsoft sealY 79,11ypally of feltsoakedinoiland retained in `opposinggrooves'in the discs,- excludes dustfrorn thevalving face 651.

'A5 means is provided for venting each ofthe ttings- 66 which; arenot in communication 'with-port P77;.V 'Ifhisi may beiaccomplished-by providing a series of-holes 86 drilled in rotating' discv 36v in: axial alignment; oneV each`V with all oi fthe ports 66 'except the one'which-isein register with port r[717. This insures thatallxot the devices to'be controlledare vented to atmosphere Lexceptthe Aone being suppliedwith pressure gas throughport-77. Y,

Base64 is securedA to thecent'ral uprightlpart 35h-y setiscrews64nl and holds theball bearingl assembly 68 against upwardl verticalj displacement: This base Vplate may suppoitafhousing 64b.v vAttached tothe base 64 is a motor cylinder 39 in which a pistonf38'isforced :against a spring 81V by gastpres'sure fed to the cylinder by pipe 33.Y Thepiston 38 has an extension 82 guided by'bush; ing 83,'slotted at 84, andprevente'd fromturning, while free'V tov slide, by akey; typicallythe nose of screw 85. A ratchet lever 49, pivote'dlat-'Srin the slot 84V of the piston" 3,8,-is arranged to` actnnildirectionally on aV series of vpins 87equalinnurlber/,to ports 66L- y TheV pins are tiir'ed'to the rotatingdisc'ona commonlrdiusto ,suit the i the return''springl SA'Iand'prOVides aprecisefs'tepping point fer-,the pjumarclV tritatiA or ratchet 1er/'er 46" seoriented Vwith' relation` to the port 66, and the' pins S'TthaitA the port '77 isV brought intoexactalignment withione port'66land piston" 3s' readies' the endjo'fits stroke abnuiag" the; Astep e9: 'At the other marrer pistii'sss" sobre; the ratchet leve'r 40 will be retracted by spring 81V more than the distance between two pins by a marginal working clearJ ance.

It is believed that the operation of this controller is apparent from the foregoing description. The pilot valve housing 61 is provided with the inlet port 30, outlet port 32 and an intermediate port connecting with pipe 33. Pilot valve 31 has two operable positions, the :first closing oi the inlet 30 while connecting the outlet 32 and pipe 33 so as to vent the latter. 'I'hesecond position of valve member 31 closes port 32 while connecting the inlet 30 with pipe 33. The pilot valve when in its raised position prevents the communication of any signal impulses or gas pressure impulses, but when allowed to fall to its lower or second position, the signal impulses are given. Thepilot valve member 31 is biased toward the position for closing outlet 32 as by gravity assisted by gas pressure but a resilient means in the form of the leaf spring 62 normally overcomes the bias to hold the valve member in position to close inlet port 30.

Timed impulses are given -by overcoming the spring 62 at timed intervals, whereby the valve member 31 can assume its lower position under the bias, and the impulse duration lasts until the spring -62 is released whereby it may return valve member 31 to its raised position.

The means for rendering ineffective the resilient means 62 includes the clock driven wheel, the weighted arm with its cam connection with the wheel, and the ratchet lever 58. A means is provided for rendering this means ineffective also in response to a clock driven wheel which may be the same wheel. This latter means includes the release lever "59 with its cam '59a engageable by the pins 44 for raising the release lever to thus rock ratchet lever 58 from position where it engages the leaf spring. This terminates the signal impulse upon a timed interval basis.

'lt will be 4appreciated that the clock mechanism need not be strong enough to directly provide a force for overcoming the resilient means 62 -because the cam 5G has an inclined face 50a which is in engagement with the pin y44- over a prolonged period, thus providing a mechanical advantage capable of raising the arm 49 slowly to the position that lever '58 hooks over spring 62. However, when the pin 44 passes over the lefthand edge of cam face 50a, as shown in Fig. 5, the arm `49 is free to move quickly under the stored energy to quickly render inelective the resilient means 62. Likewise, the release of the ratchet lever 58 from resilient means 62 is instantaneous to provide a snap action for returning the valve member 31 to its other position.

It is thus seen that the signal impulse is initiated and terminated in accordance with a time cycle. The im pulse when once generated is transmitted through the pipes '33 and 34, passages 70, 71 and 75, port 77 and connection 66 to the particular motor valve or other controlled device that is connected to the particular port 66 at the particular time.

The one of ports 66 which is in register with the port 77 is also determined in response to the signal impulse for it is transmitted through pipe 33 to lthe cylinder 39 to move the piston 38 to the right and thus advance stepwise the rotor to 'bring port 77 into register with a succeeding one of ports 66.

The controller shown in Figs. 6, 7 and 8 is designed for use in either of the arrangements of Figs. l and 2. It is very similar to the controller shown in Figs. 4 and 5, utilizing many of the identical parts, and the basic dilerence is that it is shown for controlling directly a motor valve and is equipped with means other than time controlled means yfor limiting the duration of the signal impulse. It is to be understood that while the distributor indicated in the previously described controller is not shown in Figs. 6 and 7, that the apparatus of Figs. 6 and 7 can be employed with such distributor or with a plurality of such distributors in the same manner as the other controller. 'Ihisdillustrates the versatility of the device and the means forterminating'the duration of the signal impulse in accordance with conditions other than time in order to provide a safety Ifactor as well as a factor insuring conservation of control gas and also to provide -for remote control of the device.

A base plate 64 with vfacility 90 for mounting on a pedestal as in the case of the units of Figs. 4 and 5, can also be assembled on the top extension 91 of a conventional diaphragm motor valve such as that shown in Figs. land 2. I

All parts similar to those in Figs. 4 and 5 are similarly numbered. Y Y

In vthe case of the conventional motor valve shown in Fig. 2,V .gas pressure supplied to pipe 33 passes down through a hole in boss 91 to the diaphragm 92 and thus the motor valve is opened by pressure and closed by return spring 93.

In the Figs. 6 and 7 assembly, the horizontal extensions 58el and 58b of the ratchet lever 58 are brought into use for alternative means of releasing the ratchet head, 58a lfrom engagement with the spring 62.

As described in respect of Fig. 4, a pin 44 across groove 43a will lift the weight bar 49 by cam 50, ratchet hea-d 58a will be lifted up above the edge of spring 62 and spring 60 will cause its engagement therewith and prevent accidental disengagement due to vibration. In the meantime spring 62is holding valve 31 closed up against seat 30 so that pipe 33 and the diaphragm chamber of motor valve of Fig. 2 are exhausted to atmosphere through port 32. When pin 44 passes :by the end of the inclined plane of cam 50 and the weight bar 49 drops against the stop 53, the ratchet head 58a pulls down the spring blade 62 clear of the end of the spindle of valve 31, allowing the latter to close port 32, open port 30, transfer pressure to pipe 33 and the diaphragm 92, opening the motor valve.

From this position any lforce that can disengage the ratchet head 58a @from spring 62 will Ibe sufficient to cause the reclosure of the motor valve because, while the weight Ibar is heavy enough to pull down the blade spring 62, the latter, when freed will give an instantaneous thrust upward on valve 31 and he strong enough to close port 30 against the pressure supplied to it, typically 2S p.s.i., lwith a snap action.

Thus, it will be seen, pilot valve 31 is instantaneously opened and instantaneously closed.

Method No. 1 of releasing the ratchet is by the clock on a time basis. Thus,` assuming a timing wheel speed of one revolution per day, a pin 44 is placed across the groove 43b 4.at a point which will come to the top later than the pin across the groove 43a which initiated the opening of the motor valve, then after a lapse of time, cam 59a would be lifted, rotating spindle 57 and releasing the ratchet head 58a. This time delay between the opening and closing of the motor valve, assuming slots 43e, can .be yvaried in steps of eight minutes by moving the pin 44 from slot to slot. It can also be varied in very small steps by micrometer adjustment of the relative position of cam 50 which has a travel relative t'o the weight bar for'more than the distance between two adjacent wheel slots. As previous-ly mentioned, an adjustment of one division of the serrated disk 55 moves the cam jA000 which varies the time by four seconds. This is satisfactorily small `for oil -iield usage.

Thus Iby time setting, the motor valvec an be closed any time from less than one minute to more than 23% hours after the opening, variable :by Ifour second steps. This is, of course, the same for the controller of vFigs. 4 and 5.

Method No. 2 of eiecting a ratchet release is by the arrival at the surface in a well tube of a free piston which commenced its journey from the bottom of that well with a load of fluid above it when the motor valve pressure fed'througtif'pipe I28 tothe'controllerisfcorlV nected-'also'by-*pipe 96to'port 97 to aY-unitizged"o'wl'l-VV Vpilotfvalve assembly. In t-he'flowrT a cam 98',pivoted on al center 99,-'isy normally maintained V'by a springV 100 aposition such that the curved part/of its prol jectsthrough-a slotfnpipe*` llto'i'nt'e'rcept the'pa'th of aV vfree'V piston as'zitco'riifesup theV-vvellftubing.` The cam lug v102'gabuts onel l103111521 crank'lever 104'Whose other'airr 105 isnforkd toengge the head 106 or pilot valve 107. Pilot valve 107 s urged bygjlig'ht's'pring-108 t'o'A Yclose atmospheric v exhaust lportV 109 and open-gas pressure `supply portVVA 97"hut is normallyheld its op posite alternate` position by the superior force of spring 100 acting' through lugY 102,- and lever 104 on thehead'10'6 of@ the valve stern.` Thevalve sternV has a packing gland' 110. The pressure chamber 111 is connected ,by pipe 112 witha cylinder 113 containing a piston 114 whose rod 115 is A arranged to push the ratchet head 58a off the springl62 allowing it ,toclose' the controller pilot Y31'. This is more fully described in connectionV with Figs. 6

'Referring to Figs. Gand 7 the cylinder 113, attached to the back` plate 46, Vhas alslot'ted extension in which is Y pivoted a'lever 115 acted `upon in one direction by theY spring 160 and liftstnel lug 102 away from the crank -lever 11M. Y Spring 10S then moves Ypilot valve" 107 to clofsethe ventrport 109 and open thega's supply port 97 whereupon gag isfed ito chamber 108; pipe 112,v and 'cylinder 11'3 to Vthrustiout.piston 1`14whose" piston rod 115 pivots lever A1176 whose head 11S lifts thefarm SSb're'leasing ratchetV headSSm closing port 30,1venting`the'gas'rrorn the' dia- YphragmV 92 through atmospheric exhaust-32 and closing .the motor' valve.

Y Y1119 is -a manually controlled means-of 'catching and Vholdingla free piston'when itis to be retrieved, and 120 jis' a spring buffer to 'cushion' afreerpiston arrival Yat high velocity. Y ,Methods'vNos 3 ands4 v`ofrtrippingthe ratchet and .effecting thereclosure of `the motor valve are by the use of `pressuresensitive means. v Y i Y K Referring toFig. ltherpressure which is to control the durationof the signal impulse is shownlas the casing pressure V,of the well. Line 121 connects through line 94a to the casingheadV and leads. to a cylinder 124 in which is a reciprocating piston" 123. The details are shown in `Figs'. 6fand'7. A housing '124is`atvtarched tothe controller l'baseV Vby the cylinderV 122 to which'it is screwed and has an adjustablercap 125 capable'of varying the thrust of a's'prin'gll which is assembledA betweenthe under Iside of the'eap 125 and the-shoulder 127 of a stem 128 which :is in contact atV its lower end with piston 123. Stem 128 vextends 'upwards throughv the capv 125 and carriesv adjustable'nuts 129'7arrranged'one Vabove and one be-V .low the head1130 Vof atripY arm 132Y which pivots on a pinw131 ,and'extends through slots ninthe back plane 46 to vengage 'either the left arm 58C or the rightwarrnV Stb v of the ratchet'lever.58,according'to whether trip arm13'2 visassembled Aon the right'of the braeket` .61a or, switched over 'to' theopposite end of swivelpiii 4131 and assembled .onth`e.1,e'i t'sL e.

bracket 61u, the end of it comesunder the arm4 58h so that a falling pressure acting onlpiston 123, allowing an expansion of spring 126 anda descent of the stein 12S; pivots trip/'lever 132 to lift arrnlSSb' effecting-the release of ratljlet head` 5 8v'and, asbeforefftheclosure ofthe motor valve. `Thisconstitutes method Nok 3. y w f V'NjvVhen triplever 2 132`is assembledion the' left ofthe bracket 61a, the endv of'it comes over theann 58e so that aris'ing pressure actingV on piston 123, compressingspring 1`26aud=raisfing 1sten128, pivots' it in the opposite direction pushing down'the arrnmSSc and -similarly closing the Vrfotorlvalv'e.v This constitutes method No. 4. Y Thus, the release of ratchet head '58a may be in response to either a'high or low pressure. n

AlthoughI` the pressure sensitive element, is here described asa pistonin a cylinder, the use of aexible diaphragm,.a flexible nietallic'bellows 'a'ssembly, or other equally well known *pressure sensitive elements is (contemplatd without departure from the spirit of the invention. v Y Y i Although described Vin the foregoing'. and illustrated using a weight'ba'r, itwili be understood that spring force can be substituted for the' weight' to'any extent without departing from the spirit `of the invention. For example2 if the bar where half the weight illustrated Vand urged downwards by spring means, the functioning would not be altered;v similarly, if the' spring force were YYequal tothe whole weight, the latter would be unnecessary. f 1 rorn the foregoing-it will be seen thatthis invention is one well' adapted to attain all of the ends andobjects hereinabove set forth, ltogether with' otherV advantages which are obvious and' which are inherent to the structure. v Y

It will beundersrtood that certain features and subcombinations areof utility and maybe employed without refference to other features and subconibinations. YThis is contemplated by and is within the scope of the claims. Y YAs many possible embodiments may be; made'of the invention without departing from the scopetherecf, it is Vto heY understood'that all matter/herein set forthorshown in the accompanying drawings is to beinterpreted as illustrative' and not in a; limiting sense.

' I The invention having: been described, what is claimed 1". Y'A time controller for supplying'a pneumatic impulse 'A'co'mprisingV a three-way. valveY withr itsjinlet adapted' for lconnection to a source'i'of gas under pressureand'having a rst' andsecond-outletya valve member in said Yvalve movableY between two positions, the valve member when infth'e first' of saidftwo positions'closing the inlet of the valve and owingly connecting said tw'of'outletsV and when in the secondof said two :positions closingthe VfirstA of said twoy outlets and owinglyrconneeting'the inlet to the second of said two outlets, saidvalve memberbiased torward said second positions, aresilient meansl normally urging thevalve member toward its'ir'st positionto overcome said bias, a clock driven wheel, a weight bar pivotedso thatV aY part thereofY swings upwardly and downwardly toward the resilient means, av catch pivoted to 'said weight bar partj and'having a portion engageable Vwith apart connected 'to the resilient means upon upward Vpivoting of the weight bar and to remain in engagement 'with'the" resilient means during subsequent downward pivoting lof the weight bar, cam means carried by the weightA bar and eiigag'e'able: with preselected Vportions of thecl'ock drifveriwlieel torslowly raise the bar to engage the` Vcatch with" the: resilient'means and to'V lthereafter reileasethe barl top'ivot downwardly-torender theres'ilient rriearis iuei'ectivel to bias'the valve frnernberI toilitsiirs't position, means `responsive' to movement of the' clock driven wheel to disengage the catch fromthe'resilient AineahsLeiter lapse of Aa3predetermined time interval after the weight bar'haspivoted downwardly whereby therevsi ent means returns the valvemenjtberto its tirstiposisilient means responsive to a control condition and independently of said clock driven wheel and operable to prevent engagement of the catch with the resilient means during the existence of a predetermined control condition.

2. The controller of claim 1 wherein the last mentioned means is pressure actuated in response to predetermined pressure in a pressure system.

3. The controller of claim 1 wherein the last mentioned means is pressure actuated in response to position of a mechanical element.

4. A time controller comprising valve means having a valve element with two positions to alternately supply a gas under pressure to a device and to vent said device, said valve element being biased toward one position, said valve means including resilient means urging the valve element toward its other position, a timing wheel, a Weight bar pivoted for upward and downward movement with respect to the valve means, a catch pivoted to the weight bar and engageable upon upward movement of the bar with the valve means to render the resilient means thereof ineiective to hold the valve element in its other position, said catch having a part engageable with a preselected part of the timing wheel to disengage the catch from the valve means after the weight bar has moved downwardly and a cam carried by the weight bar and engageable with a part of the timing wheel to move the bar upwardly to engage the catch with the valve means at preselected intervals.

5. The controller of claim 4 in combination with means for moving the cam means along the bar whereby the time interval between engagement and disengagement of the catch with the valve means can be adjusted without alteration of the timing wheel.

6. A time controller for supplying a pneumatic impulse comprising a three-way valve with its inlet adapted for connection to a source of gas under pressure and having a iirst and second outlet, a valve member in said valve movable between two positions, the valve member when in the rst of said two positions closing the inlet of the valve and owingly connecting said two outlets and when in the second of said two positions closing the rst of said two outlets and owingly connecting the inlet to the second of said two outlets, said valve member biased toward said second position, a resilient means normally urging the valve member toward its rst position to overcome said bias, a clock driven Wheel, a weight bar pivoted so that a part thereof swings upwardly and downwardly toward the resilient means, a catch pivoted to said weight bar part and having a portion engageablc with a part connected to the resilient means upon upward pivoting of the weight bar and to remain in engagement with the resilient means during subsequent downward pivoting of the weight bar, cam means carried by the Weight bar and engageable with preselected portions of the clock driven wheel to slowly raise the bar to engage the catch with the resilient means and to thereafter release the bar to pivot downwardly to render the resilient means ineffective to bias the valve member to its rst position and means responsive to movement of the clock driven wheel to disengage the catch from the resilient means after lapse of a predetermined time interval after the weight bar has pivoted downwardly whereby the resilient means returns the valve member to its rst position.

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